The latest articles on Forem by Serhii (@zellenka). https://forem.com/zellenka https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F74191%2Fa5ea98c5-f412-4132-988c-f0298e578763.png https://forem.com/zellenka en Serhii Mon, 16 Feb 2026 00:08:42 +0000 https://forem.com/zellenka/multiplication-master-fun-math-practice-app-for-kids-84b https://forem.com/zellenka/multiplication-master-fun-math-practice-app-for-kids-84b <p><em>This is a submission for the <a href="https://dev.to/challenges/github-2026-01-21">GitHub Copilot CLI Challenge</a></em></p> <h2> What I Built </h2> <p>Multiplication Master is a web-based application designed to help users practice and improve their multiplication skills in a fun and interactive way. The app allows users to select which numbers to practice, set a time limit per exercise, and choose the total number of exercises. It features a game mode with a timer, on-screen keyboard, instant feedback, and a summary screen to track progress.</p> <h2> Demo </h2> <p><a href="https://zellenka.github.io/multiply-table/" rel="noopener noreferrer">https://zellenka.github.io/multiply-table/</a></p> <h2> My Experience with GitHub Copilot CLI </h2> <p>I developed an educational application to help my son, who has been struggling with multiplication concepts. Using GitHub Copilot CLI, I was able to build the core functionality in approximately 10-30 minutes. Additionally, I implemented a agent that automatically checks functionality after each commit to ensure ongoing application stability and functionality. In the plans are to add a simple registration so they can challenge other classmates and track their progress.</p> devchallenge githubchallenge cli githubcopilot